
Replication archive for "Large Scale Ideal Point Estimation", by Michael Peress

ipe_PA_rep.r contains the r code to replicate the results of the paper
r0.r contains some auxiliary functions
files starting with "hou" or "sen" contain the House and Senate roll call data for the 1st through 113th congresses
dwcs.xlsx contains the DW-Nominate Common Space scores
merge_Y.dat and merge_source.dat contain the data matrix for the merged NPAT, CCES, and roll call application, stored
as a sparse matrix for efficiency
ipe_rep_video.mp4 is a video of the program running submitted for proof of replication (PA couldn’t run the program
due to a technical issue)

Users should place all files in a single directory. Running the code will automatically install the ipe package.
Note that the package calls a dll file of compiled c++ code. Because the file was compiled in 64-bit windows, it will
only work on a 64-bit windows machine. Running the file will also install various other necesary packages:
wnominate (version 1.2.5), pscl (version 1.5.5), emIRT (version 0.0.11), plyr (version 1.8.6), readxl (1.3.1),
fastmatch (1.1-0), stringr (1.4.0), and igraph (1.2.6). Running the file will produce the figures and tables in the
paper in the same directory. The program sets random seeds so that the results of the figures are reproducible accross
computers, but the timing in tables 1 and 2 will of course not reproduce exactly, but should reproduce comparisons that
differ by an order of magnitude. The code was tested in R 4.0.2 and requires about 5gb of ram. The overall running time
of the code was about 8 hours when tested, but will vary accross computers.
